The Biostatistics Core resources has an integral role in the development, execution and analysis of the research efforts of the Johns Hopkins program project in Bladder Cancer Research. The core will provide support for Program investigators in the following areas: (1) structure on the research database and interface for data entry, data retrieval and patient or sample tracking; (2) procedures to ensure data quality, integrity, and confidentiality; (3) interim reports of project progress, patient accrual, processing of specimens, completeness of data gathering, and monitoring of patient drop-out or loss of follow-up; (4) advice on any modifications that might be necessary in study design; (5) development of new statistical methods to for the progression model; (6) data analysis and interpretation; (7) assistance in the writing of reports for publication. The biostatistics core will consist of three experienced members of the division of Biostatistics in the Oncology Center and a member of the faculty of the department of Biostatistics. A working relationship already exists between the director of the core and several principle investigators of program projects. The data coordinator described in the administrative core will work closely with the biostatistics core, coordinating all aspects of data management critical to the program's success.